Condensers



July 3, 1962 J. N. HINDE 3,042,379

CONDENSERS Filed June 29, 1959 3 Sheets-Sheet 1 m s Si "1 Si, I i r July3, 1962 J. N. HINDE CONDENSERS Filed June 29, 1959 3 Sheets-Sheet 2 July3, 1962 .1. N. HINDE 3,042,379

CONDENSERS Filed June 29, 1959 3 Sheets-Sheet 5 J4 J4? 11g 114 JJ? 11g.

J5 UP /l /A/ rHf wop/ E J4 TQ/f f4 141 STRAIGHT AND LEVEL 7z we 7a i077United States Patent C) 3,042,379 CONDENSERS .lames Neison Hinde,Highiand Park, Ill., assigner to Bell & Gossett Company, a corporationof Illinois Filed June 29, 1959, Ser. No. 823,678 3 Claims. (Cl. 257-43)This application is a continuationdn-part of my copending applicationSerial No. 798,616, filed March 11, 1959.

This invention relates to condensers, and particularly to shell and tubecondensers that are adapted for use in refrigerating systems for thecondensing of refrigerant,

Condensers of the aforesaid kind have the tubes thereof disposedhorizontally within an elongated shell so that the gaseous refrigerantintroduced into the upper portion of the shell may flow downwardly overthe tubes so as to be condensed on the surface of the tubes which areusually of the finned type, :and the condensed refrigerant is withdrawnin liquid form from the lower portion of the shell.

In my aforesaid copending application, I have disclosed and claimed acondenser of the aforesaid type wherein the finned tubes of thecondenser are arranged one above the other in laterally spaced stacks sothat the gaseous refrigerant may move downwardly in passages that aredefined between the adjacent stacks, and in accordance with theinvention disclosed and claimed in said copending application, the iinsof the tubes in each stack are in substantial contact one with the otherso that effectual drainage of the condensed refrigerant is attained. Inthe aforesaid copending application the structure also provides forholding the tubes against vibration by means of U-bolts that embraceeach stack of tubes in one or more locations near the central portionsof the tubes, and the U-bolts serve to assure a proper draining relationof the adjacent finned tubes in each stack.

The present invention is an improvement on the invention disclosed andclaimed in my aforesaid copending application, and particularly, thisinvention is concerned with the arrangement and relation of the tubes ofthe condenser. In the use of condensers as disclosed in the aforesaidcopending application, the performance has been highly satisfactory froman operational standpoint, but where condensers of this kind are mountedin outdoor locations so as to require draining of the cooling water fromthe condenser during the period of non-use in the winter, the usualdraining operation does not in every instance drain the water from allof the tubes. As a result some damage to the tubes has been encountereddue to freezing of the retained water.

In view of the foregoing it is the primary object of the presentinvention to provide condensers of the aforesaid character where fulldrainage of the tubes is assured, and a further and more specific objectof the present invention is to provide a condenser embodying the advantageous characteristics of the condenser disclosed in my aforesaidcopending application and having the tubes thereof so disposed thatproper and adequate drainage of cooling water `from the tubes will takeplace in the normal draining of the cooling water system.

Another and more specific object of the present invention is to providean advantageous method of assembling condensers of the aforesaidcharacter in such a manner that the tubes thereof will drain properly.

Other and further objects of the present invention will be `apparentfrom the following description and claims, and are illustrated in theaccompanying drawings, which, by way of illustration, show a preferredembodiment of the present invention and the principles thereof, and whatis now considered to be the best mode in which to apply theseprinciples. Other embodiments of the inven- ICC tion embodying the sameor equivalent principles may be used and structural changes may be madeas desired by those skilled inthe art without departing from theinvention.

In the drawings:

FIG. 1 is a vertical sectional view taken longitudinally through `aliquid cooled condenser embodying the features of the invention;

FIG. 2 is a vertical cross sectional View of the condenser, the viewbeing taken substantially along the line 2-2 of F IG. 1;

FIG. 3 is a view showing a plurality of tubes in association with eachother and with a tube sheet;

FIG. 4 is a longitudinal sectional View that is somewhat schematic incharacter and which illustrates the first step in the assembly of thetubes on and with respect to the tube sheets;

FIG. 5 is a View similar to FIG. 4 showing the tubes after they havebeen assembled with the tube sheets and have been deformed so as to bebowed upwardly; and

FIG. 6 is a view similar to FIG. 5 after the upward bowing forces on thetubes have been released and the tubes have assumed their finalrelationship and are ready for rolling or fixing in the tube sheets.

For purposes of disclosure the invention is herein illustrated asembodied in a shell and tube type condenser 10 that comprises anelongated cylindrical shell 12 adapted to be mounted in a horizontalposition and having tube sheets 14 at opposite ends thereof, end heads16 and 18 being secured by studs 19 to the respective tube sheets 14 fordirecting the flow of cooling media such. as water through a pluralityof finned tubes 20 that extend lengthwise through the shell and aremounted at their opposite ends in tube sheets 14. The end heads 16 and18, as herein shown, are so formed as to attain a two-pass operation ofcondenser, but this is merely illustrative. In the form shown, the head16 has a liquid inlet 16A and a liquid outlet 16B, and the head 16 beingdivided between the inlet and outlet by a cross wall 16D. The head 18 ofcourse is formed without internal divisions and this arrangement thusprovides for two-pass operation. The condenser 10 has a gas inlet 22 atthe top of the shell 12 and a bottom outlet 2.4 is provided in the shellfor the discharge of condensate.

The arrangement of the tubes 20 in laterally spaced stacks S so as toachieve an unusually eicient condensing operation that is described incomplete detail in my aforesaid copending application, and thedisclosure of such copending application, is incorporated by referenceherein. It may be pointed out, however, that the ends of the tubes 20are formed without fins as at 20E, as shown particularly in FIG. 3 ofthe drawings, and these ends 20E are extended through internallyserrated openings 14B that are formed in the tube sheets 14. After thetubes 20 are in place, as will be described in some detail hereinafter,the tubes are internally rolled within the openings 14B so as tointerlock the tubes with the grooves of the openings 14B.

It has been pointed out that the tubes 20 are yarranged in stacks S thatare spaced laterally from each other and as described in detail in myaforesaid copending application, the tubes 20 have the fins F thereof insubstantial engagement with the iins F of the next adjacent tubes inlthe stack S.

In practice, in the ini-tial assembly of the tubes `2t) lin the tubesheets 14, the fins F of vertically adjacent tubes 2.0 in the stack arespaced slightly from each other, and this spacing facilitates theinsertion of the ends of the tubes into the openings 14B of the tubesheets. The spacing of the fins is obtained by arranging the openings14B that are to receive the tubes of a particular stack Patented July 3,1962 with a vertical spacing that slightly exceeds the outer diameter ofthe ns F of the tubes.

As disclosed in my aforesaid copending application, the tubes in eachstack S are clamped together in the central portions thereof by means ofone or more U-bolts so that the tubes in each stack provide a relativelyrigid assembly in which the individu-al tubes are not subject tovibration. Each U-bolt 25 extends over the tops of the stack S anddownwardly beyond the lowermost tube 20 in the stack, and cross bars 26placed on the arms of the U-bolt engage the lowermost tube and areclamped tightly by nuts 25N that are threaded onto the lower ends of thearms of the U-bolts 25` The present invention is concerned with theattainment of adequate drainage of the inside of all of the tubes 20 ofthe condenser when the condenser is drained during the period of non-usein the winer. The arrangement is such under the present invention thatsuch drainage is iachieved by making the upper one of the tubes 20 ineach stack assume either a straight horizontal 'form or slightlyupwardly bowed form, and each of the succeeding tubes downwardly in thelowermost tube in the stack assuming a substantial upward bow, as willbe evident in FIG. 1 of the drawings. Each succeeding tube above thelower tube in -a stack has a somewhat smaller curve or bow therein, asshown in FIGS. 1 and 6, and the tubes of the stacks are clamped in thisrelation by the U- bolts 25.

Under the present invention the above described larrangement andrelative configuration of the tubes Ztl of each stack S is attained in asimple manner, while Lat the same time retaining the fully clampedrelationship of the tubes 20 of the stack, whereby the proper drainageof the condensate from the ns F is assured, proper drainage of coolingwater from the inside of all of the tubes is attained, and the tubes ofeach stack are held as a substantially rigid assembly in which theindividual tubes cannot vibrate and produce noise.

The structural assembly that has thus been described, and which is shownin FIG. 1, yis produced through the series of `assembly steps that aredisclosed in FIGS. 4, 5 and 6. Thus, in FIG. 4 of the drawings, the tubesheets 14 are illustrated as being held in parallel and spaced relationand in the relative positions that they are to assume in the finishedcondenser, and these tube sheets of course have the several openings 14Bformed therein to receive the ends of the tubes 20. This location of thetube sheets 14 may be accomplished by suitable xtures of conventionalform and design.

The tubes 20 are put in position for each of the stacks S of the tubesin succession, yand FIGS. 4 to 6 illustrate the tive-tube stack that isshown at the right hand side of FIG. 2 of the drawings. Each tube 20 forthe stack is inserted through an opening in one of the tube sheets 14and is then moved in the opposite direction to insert the other end ofthe tube into the corresponding opening of the other tube sheet, andwhen this is done the tube 20 is supported in the two openings 14B, butis relatively slidable therein.

All of the tubes 20 that lare to form one of the stacks S are insertedas above described so that all of the tubes 20 of the stack may beforced to a bent or upwardly bowed relationship such as that shown inFIG. 5 of the drawings, and in this operation the tubes must be free tomove longitudinally in at least one of the tube sheets 14. With this inmind, the left end of each tube is then secured in position in the le-fthand tube sheet 14, as indicated in FIG. 4, while the other or righthand ends of the tubes remain in their slidable relation in the bores14B of the right hand tube sheet 14. Then, while the tube sheets 14 areheld in suitable fixtures as indicated by the arrows 114 in FIGS. 4, 5and 6, the tubes 20 are bent to substantially the form shown in FIG. 5.The tubes 20 of the stack S may be laterally guided or confined by asuitable fixture engaging opposite sides of the tubes of the stack, andthe upward pressure is applied, `as by hydraulic means, midway betweenthe `ends 0f the tubes so -as to force the bottom tube 20 upwardly.

The upward pressure is applied substantially at the point indicated bythe arrow in FIG. 5, and the several tubes 2) of the stack are bent ordeformed upwardly to such an extent that the midpoint of the upper tube2t) of the stack is somewhat above the plane of the ends of the stack, aone inch over-bend being indicated as an example in FIG. 5. In otherwords, all of the tubes of the stack are overbent or over-stressedbeyond the relationship which they are to assume in the finishedcondenser. As the bending takes place, of course, the free or right handend portions of the tubes may slide, yas required, within the open-ings14B of the right hand tube sheet. After the stack S of tubes have beenbent upwardly to substantially the relationship shown in FIG. 5, theclamping means, which as shown constitute a single U-bo'lt 25, is put inposition as indicated in FIG. 5, and after putting the cross bar 26 inposition, the nuts 25N thereof are clamped so that the mid-portions ofthe tubes 20 have the fins F thereof in physical engagement with eachother and the tubes Ztl of the stack are eiectually united as asubstantially rigid unit, particularly tat the midportions thereof.

After the U-bolt 25 has been tighte-ned with the parts in therelationship shown in FIG. 5, the lifting force that has been applied at12) as illustrated in FIG. 5, is released. When this is done, the stackof tubes 20 tends to return from the overbent or overstressedrelationship shown in FIG. 5, and it may be noted that the overbendingis carried to the extent required to cause the stack of tubes to returnto a relationship where the uppermost tube 20 of the stack issubstantially straight or is bowed slightly in an upward direction.During the foregoing operation, the tube sheets 14 are maintained intheir xed original relationship, and as the stack of tubes 20 returnsfrom its overbent relation, the free or right hand end portion of thetubes may move as required in an endwise relationship in the opening 14Bof the tube sheets.

The tubes 20 are then ready for anchoring of the other or right handends in the tube sheets, and this is accomplished in the usual manner asby internal rolling of the end portions of the tubes 20 within theopenings 14B, thus to provide external annular beads that engage withthe internal serrations of the openings 14B. The projecting ends of thetubes may then be trimmed.

The assembly of the other stacks of tubes 20 is then carried out insuccesison in a imilar manner until all of the tubes 20 have been putinto position between the tube sheets 14. The assembly then constitutesa rigid assembly wherein the tube sheets 14 are rigidly interconnectedby the several stacks of tubes 20, and the asesmbly is thus in conditionfor application of the shell 12 and the related parts to produce thecomplete condenser.

It may be noted that while both ends 0f the tubes 20 might be left yfreefor endwise movement in the tube sheets during the bending and clampingoperations, the procedure is simplied by rst securing one end of eachtube in position as above described. Thus by this procedure, theoriginally ecured ends of the tubes do not require trimming; overpullingof the tubes in one of the tube sheets is avoided, and the tubes areheld against twisting or turning during the application and release ofthe bending forces.

From the foregoing it will be apparent that the present inventionprovides an improved Iwater cooled condenser wherein the nned tubes areso arranged that there is not only a great increase in the eiciency ofthe condensing action, but also the tubes are clamped together in such away that the tubes cannot vibrate and cooling water will be drainedproperly from the tubes during the periods of non-use in the winter.

It will also be apparent that the present invention provides the new andhighly advantageous method of assembly of condensers whereby the tubesmay be arranged and clamped in such a way as to assure proper drainageof the tube.

Thus while I have illustrated a preferred embodiment of the invention,it is to be understood that changes and variations may be made by thoseskilled in the art without departing from the spirit and scope of theappended claims.

-I claim:

1. In ashell and tube condenser, a casing including a shell and tubesheets with housings associated with `the tube sheets to provide coolantinlet and outlet passages and said shell having a top inlet for gas anda lower outlet for condensate, a plurality of fnned tubes connectingsaid tube sheets within such shell, said tubes being arranged inlaterally spaced vertical stacks with the tins of vertically adjacenttubes in said stacks being in substantial engagement one with the other,and means clamping the tubes of each stack together adjacent tomidpoints of the stacks with the upper tube of each stack substantiallystraight and with the successive tubes downwardly of said upper tubebeing curved into an upwardly bowed arrangement so that the lower tubehas the greatest upward bow and all of the tubes of each stack aremaintained in a substantially rigid relationship to each other.

2. In a shell and tube condenser, a shell and tube sheets with housingsassociated with the tube sheets to provide coolant inlet and outletpassages, said shell having a gas inlet and a condensate outlet, aplurality of iinned tubes such shell extending between and through saidtube sheets, said tubes being ararnged in laterally spaced verticalstacks with the ns of vertically adjacent tubes in said stacks being linsubstantial engagement one with the other, and U-bolts embracing therespective stacks and clamping the tubes of each stack together adjacentto midpoints of the stacks with the upper tube of each stacksubstantially straight and with the tubes downwardly of said upper tubebeing curved into an upwardly bowed arrangement.

3. In a shell and tube condenser, a casing including a shell and tu-besheets with housings associated with the tube sheets to provide coolantinlet and outlet passages, said shell having a top inlet for gas and alower outlet for condensate, a plurality of finned tubes extendedbetween and through said tube sheets, said tubes being arranged inlaterally spaced vertical stacks with the fins of vertically adjacenttubes in said stacks being in substantial engagement one with the other,and means embracing the tubes' of each stack as a group and clampingsuch tubes together, in the central portions ofthe stacks all of thetubes below the upper tube of the stack being curved into an upwardlybowed arrangement and with the upper tube substantially straight.

References Cited in the tile of this patent UNITED STATES PATENTS1,363,208 Serck Dec. 21, 1920 1,550,368 Kirgan Aug. 18, 1925 1,641,975Jones Sept. 13, 1927 1,741,121 Winslow Dec. 24, 1929 1,780,781 EhrhartNov. 4, 1930 1,788,386 Ehrhart Ian. 13, 1931 2,176,876 Hughes Oct. 24,1939 2,720,383 Huet Oct. 11, 1955 2,830,797 Garland Apr. 15, 1958FOREIGN PATENTS 310,327 Great Britain July 16, 1930

